Dynamic legal database providing historical and current versions of bodies of law

ABSTRACT

Information collections defining a common subject such as a codified or uncodified body of law are stored on a computer readable medium in association with temporal information indicating the state or status with respect to time of parts of the information collection, including different versions of the same part. Parts of an information collection that are different versions of each other have different temporal information associated therewith and can be accessed based on the temporal information. Thus, the temporal information may be used to control access to and display of parts of the subject in a computer system based on time as search or request parameter. In a preferred embodiment, the subject is a statutory body of law such as the United States Code. Sections of the Code are stored in association with temporal information such as date of enactment, effective date and termination date. A researcher can access a version of any part of the Code in effect at any particular time.

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent files or records, but otherwise reserves all copyrightrights whatsoever.

BACKGROUND OF INVENTION

The invention generally relates to collections of information and tosystems that include, and/or access, retrieve, display and/or otherwiseperform operations involving, such information collections. Inparticular, the invention relates to information collections thatinclude information that may change with time, and which maintain astatus, state or other relationship of information in the collectionwith respect to time. For example, the information collections may storehistorical as well as current information in association with relatedtemporal information. In preferred embodiments, the informationcollections comprise a body of law and store historical and currentversions of the body of law and parts thereof.

The term “information collection” is used herein in a broad sense and,unless the context indicates otherwise, encompasses databases,information bases, knowledge bases, bodies of information, etc., storedon a computer readable medium (electronic, magnetic, optical, etc.) orotherwise accessible by a computer device. Similarly “information” isused herein in a broad sense and, unless the context indicatesotherwise, encompasses data. Unless the context indicates otherwise, theterms “information” and “data” may be used herein interchangeably, andthe terms “information collection,” information base,” “knowledge base”and “database” may be used herein interchangeably. Similarly, the term“body of law” is used herein in a broad sense and encompasses bodies oflaw, codified and uncodified, such as codes, sets and codifications oflaws, regulations, administrative rules, etc.

Some information collections include information that changes with time,and, in a sense, are dynamic. For example, a dictionary is a collectionof words and their meanings; both the composition of the collection andthe meanings of words in the collection may change over time.Frequently, words have multiple meanings in dictionaries and includehistorical information. Other examples are version control andconfiguration management systems that include historical and currentversions of documents and software.

Still another example of an information collection that may change overtime is a body of law, for example, promulgated by a governmental orquasi-governmental or other organization.

Such information collections may include historical information in theform of commentary, historical data, annotations, legislative history,references to other laws or judicial decisions, case notes, etc., aswell as the current version of the body of law.

In the above examples, the subjects of the information collections canbe rather large. To facilitate working (e.g., storing, accessing,retrieving, displaying, etc.) with an expansive subject, it is oftennecessary to provide some kind of organizational structure for theinformation. For some applications of a dynamic subject that may changeover time, not only would an organizational structure be beneficial, butit would be useful to be able to track status or obtain the currentstate of parts of the subject, or to obtain historical information suchas earlier versions of parts of the subject.

Bodies of law and/or parts thereof typically take effect on some dateafter enactment, and remain in effect until a specified expiration date,or indefinitely (or in perpetuity), unless altered or terminated by anintervening enactment. However, some bodies of law and/or parts thereofhave retroactive effect from the date of enactment. In addition, at thetime of enactment, a body of law or part thereof may have a durationthat is not certain. For example, a body of law or part thereof becomesand/or ceases to be effective at some time triggered by an event that isnot certain at the time that the body of law or part thereof wasenacted. Possibly, such a body of law or part thereof might neveractually go into effect if its initial effective conditions are not met.Likewise, a termination condition could fail to occur. It is alsopossible that a body of law or part thereof might be enacted with aneffective date that, because of a subsequent enactment, may never takeeffect.

Therefore, ascertaining the status or state of any body of law or partthereof at any given time or interval of time can be difficult. Also,many bodies of law typically include one or more parts and/or sub-partsthat may be modified independently of each other, which can compound anyuncertainty or lack of clarity in the status or state of the parts andsub-parts.

SUMMARY OF INVENTION

The invention provides information collections that include informationthat may change with time, and which maintain a status or state or otherrelationship(s) of information in the collection with respect to time.The information collections may define a body of information on a commonsubject, e.g., a body of law, and the state or status thereof at anygiven time or within any given period of time, and provide access to aversion of a part of the common subject that is or was active, or is orwas applicable, or as it read, etc., at any given time or within anygiven period of time.

The invention provides a dynamic or date-sensitive informationcollection that cohesively provides access to a subject, e.g., fordisplay, printing, storage, processing, etc., based on temporalconcerns. For example, the information collections may store historicalas well as current information in an integrated fashion.

As discussed below, a plurality of parts of the common subject areassociated with temporal information indicating a state or statusthereof, e.g., a temporal applicability with respect to time, with whichaccess for retrieval, transmission, storage, display, printing, viewing,etc., is affected or controlled, or by, with or through which a part ismade visible to a user in some way (collectively referred to herein as“visibility” for ease of reference and discussion). Other information,e.g., historical information, commentary, annotations, descriptiveinformation, references and/or links to other parts of the subject or toother subjects, etc., may also be associated with parts of the commonsubject. For example, visibility of a part or parts of a common subjectwill depend upon the temporal information associated therewith.Visibility is a user-centric concept in which information stored inassociation with temporal information on a computer readable medium mayor may not be accessible to a user, e.g., for retrieval, transmission,storage, display, printing and/or viewing based on one or morepredetermined criteria. Thus, temporal information can be used as afilter so that only that part or those parts of the subject that satisfya temporal criterion or criteria would be visible.

The inventive information collections are stored on a computer readablemedium, and comprise a plurality of unique parts of information, eachrelated to a common subject, e.g., a body of law, and each stored inassociation with temporal information of the type described herein. Apart of a collection may be an atomic part that is not subdivided, or anon-atomic part that is subdivided. An example of a non-atomic part is atable of contents (“TOC”) or index heading, while an example of anatomic part is a lowest level unit under the heading. The collectionsinclude a plurality of parts of the common subject that are differentversions of each other (including parts which are replacements orsubstitutes for other parts, or parts that are the closest counterpartof other parts, etc.), and have different temporal informationassociated therewith. Different versions of the same part are alsoexamples of atomic parts.

The collections are preferably arranged or configured to include aplurality of topics, each having associated therewith at least one partof the common subject and including information relating to the at leastone part of the common subject. A topic may be atomic or non-atomic, andmay simply be an identifier for a part of the common subject, or a namefor such part, or a heading, for example in a TOC or index, etc. Atleast one of the topics has associated therewith a plurality of parts,e.g., atomic parts, of the common subject that are different versions ofeach other and that have different temporal information associatedtherewith. Information associated with a topic may include temporalinformation relating to the applicability with respect to time of atleast one of the parts associated with the respective topic and/orhistorical information, descriptive information, etc. relating to such apart and/or the associated topic.

A part of the common subject and temporal and other information can beassociated in various ways. They can be linked (e.g., hyperlinked) orincluded in the same file, or record or structured document, or they maybe associated by pointers, etc. Topics and related parts of the commonsubject and other topics can be similarly associated.

In one embodiment, the information collection is represented by ahierarchical arrangement of topics and associated parts of the commonsubject. The information collection may be hierarchically organized as atopic tree having non-leaf nodes and leaf nodes representing topics. Anon-leaf node is an example of a non-atomic topic and a leaf node is anexample of an atomic topic. Each atomic part of the common subjectassociated with a respective topic is associated with the leaf noderepresenting that topic. At least one TOC or index may be associatedwith at least one topic, each TOC or index including a reference to eachpart of the common subject associated with the respective topic. Atleast one heading in the TOC or index is a leaf node associated with aplurality of atomic parts of the common subject that are differentversions of each other and have different temporal informationassociated therewith. Each atomic part of the common subject isassociated with at least one heading. The headings may have temporalinformation associated therewith that indicate the temporalapplicability of the part of the common subject associated therewith, aswell as other information. Non-atomic headings or topics may includepointers to atomic parts, or be associated in any appropriate manner.

The temporal information associated with each part of the common subjectmay include a date range, and in that embodiment, the informationcollection is structured so that a part of the common subject can beaccessed based on a date encompassed by the date range associated withthat part. The date range may include a date on which that part of thecommon subject first became effective, or was the then or now currentversion. If the part of the common subject has a date when it ceases tobe effective or current, or a date of termination, which may be unstatedand hence would be indefinite or in perpetuity, the date range may alsoinclude that date. The temporal information may also include a date onwhich the part of common subject was created or adopted, which may alsobe included in the date range.

Parts of the common subject, and topics if applicable, may be includedin structured documents, e.g. created with a markup language such asExtensible Markup Language (“XML”) or Hypertext Markup Language(“HTML”). In such an embodiment, each part of the common subject that isa different version of the same part is preferably included in aseparate structured document. A document can be or include an atomicpart of a common subject, or a non-atomic part of a common subject. Apart or document may include information or content in various forms,including by way of example, any or all of text, numbers, symbols,computer code, graphics, etc. While a document may contain a non-atomicpart of the information collection, the document itself may not besubject to subdivision. Structured documents may include topics,headings, parts, etc., and may also include references to other relatedor associated documents.

In one embodiment, each part of the common subject and its associatedtemporal information are included in a separate lower level structureddocument. One or more higher level structured documents includeinformation relating to a plurality of lower level structured documentsthat are in a hierarchical relationship with a respective higher leveldocument. At least one of the higher level documents has informationrelating to a plurality of lower level documents that each includes adifferent atomic version of the same part of the common subject and theassociated temporal information. At least one higher level document mayinclude a topic and/or a TOC including a reference to a lower leveldocument or documents associated therewith. At least one higher leveldocument may include a topic and/or a TOC having a reference to one ormore other higher level documents and to one or more lower leveldocuments which are referenced by any of the plurality of higher leveldocuments. The documents in this embodiment are hierarchically relatedin ancestral and descendant relationships. Also, at least one structureddocument may be provided indicating differences between differentversions of the same part of the common subject.

The invention provides methods of providing the information collectionsdescribed herein comprising: associating each part of the common subjectwith applicable temporal information, organizing parts of the commonsubject into topics at least one of which includes a plurality of atomicparts that are different versions of each other, and configuring theinformation collection to provide, in response to at least one requestidentifying a part and/or topic and/or a date, the identified partand/or topic having temporal information associated therewith thatencompasses the date. The terms “request” and “query” are used in abroad sense and encompass inputs entered into a computer or computersystem or equivalent device by any appropriate input device, includingselection of input information displayed on a computer display using apointing device such as a mouse. Also, a request may be entered by asingle input, multiple inputs or a series or sequence of inputs.

In embodiments providing an information collection in structureddocuments, an inventive method comprises: associating each part of thecommon subject with applicable temporal information by including eachpart and its associated temporal information into a lower levelstructured document; associating applicable lower level documents with ahigher level structured document by including in each higher leveldocument information relating to one or more lower level documentassociated therewith; and configuring the information collection toprovide, in response to at least one request identifying a part of thecommon subject and a date, a structured document including theidentified part having temporal information associated therewith thatencompasses the date.

Each part of the common subject is preferably stored discretely and theinformation collection preferably includes a construct for implementinga topic tree. The topic tree, which organizes the parts of the commonsubject according to a predetermined organization scheme, includes leafnodes which represent the finest, smallest or most granularorganizational breakdown, i.e., atomic parts. The atomic parts of thecommon subject are logically or relationally associated with the leafnodes, which represent the atomic topics. Each non-root node of thetopic tree may be logically associated with temporal informationreflecting the temporal scope of the nodes and parts of the commonsubject associated therewith.

In the preferred embodiment, the topic tree is implemented by ahierarchical arrangement of structured documents which collectivelyprovide a TOC. The parts of the common subject are provided instructured documents, and the TOC is also provided in structureddocuments that are logically positioned at nodes of the topic tree andinclude references to corresponding structured documents. In addition,each TOC document preferably includes a reference to an ancestral (e.g.,parent) TOC document, if any, and all descendant (e.g., child) TOCdocuments. Each document reference in a TOC document preferablyincludes: (i) a label, reflecting an instance of a heading in the TOC;(ii) a file name of the referenced document; and (iii) a date rangereflecting the combined temporal scope of all documents which descendlineally from the referenced document. In this manner, the label (whichrepresents an entry or heading in the table of contents) can bedisplayed depending on its visibility.

The invention also provides systems for storing and accessing parts of acommon subject having temporal information associated therewith. Suchsystems comprise an information collection as described herein stored ona computer readable medium, and means for accessing a part from theinformation collection in response to at least one request identifyingthe part and a date encompassed by the temporal information associatedwith that part. Such means may include a computer system comprising atleast one computer, at least one computer display device and at leastone computer input device.

A part of the common subject may be accessed in various ways. One way isto navigate to a display of interested parts along a hierarchical path(e.g., along a topic tree) until an identification or indication of thepart of interest or versions thereof is reached. At that point, the partof interest can be selected. Alternatively, a part, topic or heading canbe identified, and then navigation can proceed to the part of interest.If the identity of the part is known, navigation to a version canproceed directly by inputting the identity of that part. Navigation canbe filtered at each level by temporal information.

In one embodiment, dates are displayed on a computer display device inassociation with at least an identity of a plurality of parts of thecommon subject that are different versions of each other, or a topic orheading related to the plurality of parts is displayed in associationwith dates. The part of interest can then be selected and accessed basedon the displayed temporal information. In another embodiment, a part ofthe common subject and a date are input to the computer, and in responsethereto, the computer accesses that part whose identity was input to thecomputer having temporal information encompassing the inputted date.Selection can be made, and search or request information or criteria canbe input, using the computer input device. The collections may provideaccess to parts thereof for visibility purposes, as discussed herein,and for other purposes.

In a preferred embodiment, the subject is a codified body of law. Acodified body of law may comprise the United States Code and/or theUnited States Code of Federal Regulations, state law codifications(e.g., New York Civil Procedure Law and Rules), regulations of state andfederal administrative bodies, etc, and/or a title or chapter, etc.,thereof These collections can provide access to a version of any part ofthe body of law based on the temporal information associated therewith.(Similarly, a common subject, not strictly a body of law, may be a setof rules and regulations, or bylaws, for a governmental,quasi-governmental or non-governmental organization.)

With respect to a codified body of law, a part thereof may be a title,chapter, section, or a subsection or paragraph of a section, etc. Forexample, a title, chapter or a section may be considered non-atomicparts, and a section or subsection or paragraph thereof may beconsidered atomic parts, depending upon how the collection isconfigured.

Temporal information stored in association with a part of a body of lawmay include a date or date range, as discussed above. Where the temporalinformation includes a date range, the date range may include a date onwhich the concerned part of the body of law is effective, and if thatpart of the body of law has a date of termination, the date rangeincludes the date of termination, which may be unstated, and henceindefinite, or in perpetuity. The temporal information may also includea date on which the part of body of law was adopted, or enacted, whichmay be included in the date range. Other information stored inassociation with a part of a body of law may include historicalinformation, commentary, annotations, descriptive information,legislative history, references, and/or links to laws and judicialdecisions.

Inventive information collections may comprise unique units ofinformation or subject matter that define the common subject, where eachinformation unit includes or consists of a part of the common subject,and is stored in association with temporal information of the typedescribed herein, and can be stored with other information of the typedescribed herein, and other information. In a preferred embodiment, aninformation unit includes at least the associated temporal information.Similarly, inventive information collections may comprise unique topicalunits including or consisting of a topic, and may be stored withtemporal information associated with the topic and/or any part orinformation unit associated with the topic, and other relatedinformation.

The description above with respect to parts and topics of a commonsubject applies to information units and topical units. For example, aninformation collection is structured so that an information unit can beaccessed based at least on the temporal information associatedtherewith, and in an embodiment including topical units, the informationcollection is structured so that an information unit can be accessedbased not only on the temporal information associated therewith, butalso through a topical unit. Also, information units and topical unitscan be associated with temporal information, other information and/orother units in various ways. They can be linked (e.g., hyperlinked) orincluded in the same file, or record or structured document, orassociated by pointers, etc. Information collections defined byinformation units and topical units can be stored and organized asdescribed above. As discussed above in connection with parts of a commonsubject, information units and associated temporal information, andother information, if applicable, and topical units and associatedtemporal information, and other information, if applicable, may behierarchically organized as described above, and may be included instructured documents as described above.

BRIEF DESCRIPTION OF DRAWINGS

The foregoing and other aspects of the invention will become morereadily apparent from the following description of illustrativeembodiments thereof and the accompanying drawings, which illustrate theinvention in an exemplary and non-limiting fashion. In the drawings:

FIGS. 1 and 1A are schematic diagrams illustrating a hierarchical treestructure for arranging data having temporal information associatedtherewith in an information collection according to the invention;

FIGS. 2A and 2B are schematic diagrams illustrating other structures forarranging data having temporal information associated therewith in aninformation collection according to the invention;

FIG. 2C is a schematic diagram illustrating data having temporalinformation associated therewith arranged in a relational databasestructure according to the invention;

FIG. 3 is a schematic diagram illustrating data arranged in ahierarchical tree structure, similar to that depicted in FIG. 1, intowhich the United States Code and other bodies of law or informationcollections can be arranged in accordance with the invention;

FIG. 4 is a schematic diagram illustrating data arranged in ahierarchical tree structure, similar to that depicted in FIG. 1, where,however, not all of the data has temporal information associatedtherewith;

FIG. 5 is a schematic diagram illustrating a document structure intowhich the United Sates Code or other body of law or informationcollection can be arranged in accordance with the invention;

FIGS. 6A, 6B and 6C are diagrams that illustrate temporal applicabilityof parts of the United States Code body of law represented in FIG. 5;

FIG. 7 is a block diagram of a system according to the invention inwhich the United States Code body of law represented in FIG. 5 isstored, accessed, retrieved and displayed in accordance with theinvention;

FIGS. 8-15 illustrate various screen displays of data from the UnitedStates Code body of law represented in FIG. 5, and menu selections inFIGS. 8-14 for other bodies of law provided by the system depicted inFIG. 7;

FIG. 16 is a flowchart of a process for updating a body of law, such asthe United States Code represented in FIG. 5, when an existing partthereof is modified; and

FIG. 17 is a table of classifications for the United States Codeproduced by the Office of the Law Revision Counsel, U.S. House ofRepresentatives.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A general structure, according to one embodiment of the invention, of aninformation collection 10 that changes with time is represented inFIG. 1. The information collection 10 defines a body of information on acommon subject, e.g., a body of law. Although the description belowfocuses on information collections defining a body of law, it should beunderstood that the invention is not limited thereto and applies toother bodies of information on a common subject. The visibility of partsof the body of information depends upon the temporal informationassociated therewith. The parts may be stored or organized in variousways, e.g., hierarchically.

The information collection 10 represented in FIG. 1 comprises uniqueparts of the common subject included in unique information (or subjectmatter) units referenced generally by 14. FIG. 1 depicts a hierarchicaltree structure comprising a topic tree 20 that includes the informationunits 14. The topic tree 20 organizes or classifies the informationunits 14 according to an organizational scheme(s) or a pre-determinedorganizational structure that includes non-leaf nodes 24 and leaf nodes26. The non-leaf nodes 24 (shown as smaller filled-in circles) of thetree 20 represent non-atomic topical units 24 which can be subdividedinto smaller or more granular sub-topics, e.g. atomic topical units 26,by branches 27. (The same reference number “24” is used to refer tonon-leaf nodes and non-atomic topical units.) The leaf nodes 26 (shownas larger unfilled circles) of the tree 20 represent atomic topicalunits which are not subject to further organizational breakdown. (Thesame reference number “26” is used to refer to leaf nodes and atomictopical units.) The atomic topical units 26 thus represent the finest ormost granular level of the organizational structure embodied in thetree. Some leaf nodes 24 have a plurality of leaves in the form ofinformation units 14 a, 14 b, 14 c connected thereto by stems 28. Thus,each atomic-topical unit 24 is associated with at least one informationunit 14, and some have a plurality of information unites 14 a, 14 b, 14c, each of which includes or consists of a different version of the samepart of the common subject, as discussed above.

To accommodate changes in the information collection 10 with time, thetopic tree 20 is dynamic in nature. As such, information units 14 may beadded to or deleted from the atomic topical units (leaf nodes) 26.Similarly, new branches 27 and/or nodes 24, 26 may be added to the tree,and existing branches and/or nodes may be deleted or moved to otherpositions in the tree. An example of this is shown in FIG. 1A wheretopic tree 20 a includes a new branch 30 added to the topic tree 20depicted in FIG. 1.

As shown in FIGS. 1 and 2, nodes 24 and 26, branches 27, stems 28 andinformation units 14 of the topic tree may be associated with temporalinformation, schematically represented by the “[]” symbols, that affectthe visibility of the nodes, branches, or information units. Temporalinformation associated with a non-leaf node 24 or topical unit 24 isreferenced by 16 while temporal information associated with a leaf nodeor topical unit 26 or an information unit 14 is referenced by 17.Temporal information associated with a node 26 may include the temporalinformation represented by 17 associated with each stem 28 (andinformation unit 14 connected to that stem). Temporal informationassociated with a node 24 may include the temporal informationrepresented by 16 associated with branches connected to that node, andthe temporal information associated with each other node connected tothat branch. Thus, temporal information associated with a node or branchis preferably based on the collective temporal information associatedwith all information units that lineally descend from that node orbranch, but may be independent thereof if desired.

The topic tree 20 depicted in FIG. 1 may be provided or encoded as adiscrete hierarchical construct in the information collection, or ahierarchy can be inherent through the manner in which the informationunits 14 are defined. For example, FIG. 2A shows a representation of aninformation collection 10 that does not have an express or discretehierarchical data structure for a topic tree, but has identifiable datastructures for information units 14, which encompass parts of a commonsubject. For example, the information units 14 can include the content(e.g., text, numbers, symbols, computer code, graphics) of distinctparts of the common subject. Nevertheless, a hierarchical structure isinherently present because the subject is of a hierarchical nature, asfor example a body of law codified via a systematic numbering andorganizational structure (e.g., the body of law has been organized into“titles” and “sections”).

For example, the S_(i,j) notation in FIG. 2A is one way to denote thatthe information units 14 represent or include different versions of thesame part of the common subject. S_(i) and S_(i+/−1) denote an i^(th),and i^(th+/−1) part of the common subject. However, because theinformation collection 10 in FIG. 2A is dynamic and changes with time,i.e., is date-sensitive, there may be multiple versions (or instances)of a part S_(i) and S_(i+/−1) of the common subject, which will occurwhen that part changes one or more times. The notation S_(i,j) is usedto denote a j^(th) version of an i^(th) section of the particular part.Each information unit 14 is preferably distinct and has temporalinformation associated therewith indicating its temporal applicability,i.e., for the period of time (temporal status) that the part included ineach information unit 14 is applicable (as may be indicated by the valueof the j index). Each information unit is unique by virtue of itscontent or the temporal information associated therewith, or both.

The information units 14 need not be physically distinct, e.g., storedin separate files or even different records or fields of a database, aslong as temporal information is associated with the information unit.FIG. 2B depicts a representation of a portion of such an embodiment ofan information collection 10, where the “<>” symbols represent anembedded markup language used to format a file or document 40, where iand j denote the information described above. The format represented inFIG. 2B provides an alternate way of organizing a subject into unique,identifiable information units or parts. The applicable informationunits or parts of the subject for a given date can then be displayedusing the embedded information, filtering and/or selection techniques.For example, with respect to the U.S. code body of law, the state of anysection of the U.S. Code, or a higher level overview of one or moretitles, or the U.S. Code itself, as it existed on any given date may bedisplayed.

In another embodiment represented in FIG. 2C, an information collection10 is provided by a relational database that stores a body ofinformation on a common subject. In this embodiment, each record 50 maybe the equivalent of a topical unit or node in a topic tree andrepresent a distinct part of the subject (e.g., a section of the U.S.Code), and each field 52 may hold a different version or instance ofthat part of the subject. Thus, the S_(i,j) notation discussed aboveapplies to FIG. 2C. In another embodiment, a record may represent aninformation unit and include the content of a part of the commonsubject, the associated temporal information and other information ofthe type described herein.

Preferably, however, a construct such as a data structure is provided toembody the topic tree and forms an integral part of the informationcollection. This conveniently allows the topic tree to be displayed to auser and employed as an aid in navigating through the information base.

One embodiment of the invention is a legal information collection ordatabase in the form of a body of law comprising the U.S. Code. Forexample, as shown in FIG. 3, a topic tree 20 b for an informationcollection 10 defining the U.S. Code may be constructed using ahierarchy comprising: a root (or “starting point”) node 24 a, Titlenodes 24 b, Chapter nodes 24 c, Subchapter nodes 24 d, etc., and Sectionnodes 26 of the U.S. Code. In this case, the atomic topical unit 26 is asection of code, and the leaf nodes 26 point to the information unit orunits 14 which store the text of each version or instance of a sectionof the code. For example, using the notation discussed above inconnection with FIG. 2A, S_(i) and S_(i+/−1) denote an ith, and ith+/−1sections of the Code, and S_(i,j) is used to denote a jth version of anith section of the particular section of the Code.

Unless the context indicates otherwise, the term “section” of code isused to denote a numbered portion of the code without reference tochanges in the text thereof. A version of a section of code, (sometimesreferred to as a “unit of code”), has temporal information associatedtherewith that provides a temporal aspect to the particular versionwhich thereby represents a section of code as it reads on a particulardate or range of dates.

Information collection 10 represented in FIG. 3 associates temporalinformation not only with the information units 14 thereof but also withnodes 24 (except the root node 24 a) and nodes 26 of the topic tree.Each information unit 14 and node 24 b, 24 c, 24 d and 26 in FIG. 3 isassociated with temporal information 16 or 17 indicating theapplicability thereof with respect to time. Thus, in informationcollection 10 represented in FIG. 3, the visibility of the nodes (exceptroot node 24 a) and information units 14 of the topic tree 20 b isdependent upon the associated temporal information, and can be accessedbased on a date or time period encompassed in the temporal information.These nodes may be associated with names, labels or headings of anindexing or classification system which are displayable for the purposesof navigation, thus making the indexing or classification system alsodate-sensitive. In FIG. 3, these labels represent or are instances ofthe names of the titles, chapters and sections of the U.S. Code.

In practice, a topic tree for the U.S. Code is not balanced orsymmetrical as generally illustrated in FIG. 3, and would comprise anon-uniform hierarchy because the codification is in fact more complexthan shown in FIG. 3.

In FIGS. 1-3, the temporal applicability of a part of the body ofinformation or an information unit 14 or topical unit 24, 26 ispreferably denoted by a date range. Unless the context indicatesotherwise, the term “date range” is meant in a broad sense andencompasses any scheme or system which allows the temporal applicabilityof a part of a body of information defining a common subject, or aninformation unit or topical unit to be determined. For example, withreference to temporal information associated with information units 14,a date range can be explicitly denoted by two dates, t1 and t2, orimplicitly denoted by one date, t3, which indicates that the informationunit can be visible from time t3 to present. A scheme can also be set upin which information units that are related in a pre-defined manner areeach associated with a single date, whereby a date range can be inferredfrom a difference between successive information units. For instance,information units 14A and 14B in FIG. 1, which are associated with thesame topical unit 26, can have sequence numbers indicating theirtemporal order. If unit 14B has date t4, and unit 14A has date t5,t5>t4, then the temporal applicability of unit 14B can be inferred as t4to t5 and the temporal applicability of unit 14A is t5 to present.

Furthermore, unless the context indicates otherwise, the term “date” ismeant in a broad sense and encompasses not only calendar days, butadditionally or alternatively, time, and vice verse. For example, unlessthe context indicates otherwise, “date” can be real as “time” to allowfor distinguishing one part of a day from another. For example, 12:00 PMEST on Apr. 10, 2001 is consistent with the term “date” as meant herein.

Portions of an information collection can be temporarily static orportions of a topic tree can be temporally static, i.e., not have anytemporal information associated therewith, as shown, for example, in theinformation collection 10 represented in FIG. 4. In the topic tree 20Cdepicted in FIG. 4, only the information units 14 a, b, c are associatedwith temporal information 16.

In the foregoing embodiments, the information units 14 preferablycomprise textual information, including associated temporalapplicability information. However, in alternative embodiments, theinformation units may omit temporal applicability information. In thatcase, the information units are associated with separate temporalapplicability information not included in the information units, forexample by links, pointers, etc. Information units may additionally oralternatively include, or be associated with, other types of data suchas graphical, audio and/or video data. Further, an information unit canitself comprise a combination of another or other information units.Techniques for associating, encapsulating, linking, pointing to, etc.,data and information in various programming languages are known to thosehaving ordinary skill in the programming arts.

United States Code Database System

The Database

As mentioned, in one embodiment of the invention, the subject is a bodyof law, such as the U.S. Code. FIG. 5 illustrates a preferred embodimentof a data or document architecture of the U.S. Code database 100. Thedatabase 100 comprises two kinds of documents: table of contents (TOC)documents 102 (which collectively include documents 102A, 102B . . . ),and subject matter documents 104. In a topical tree embodiment, the TOCdocuments 102 embody nodes 24, 26, for example as described above, andthe subject matter documents 104 (which collectively include 104A, 104B. . . ) embody subject matter or information units 14, for example, asdescribed above, which in this embodiment comprise units of the U.S.Code.

The TOC documents 102 are organized in a hierarchy. Except for a rootTOC document 102A, each TOC document 102 includes a file reference 107that specifies at least a parent TOC document 102 from which the formerdepends or descends. In addition, each TOC document includes a documentreference 108 to each child document directly dependent therefrom, whichcan be a child TOC document 102 or a subject matter document 104. (Thedependencies are schematically illustrated in FIG. 5 by lines 106.) Thehierarchical structure is logically similar to the topic tree depictedin FIG. 3 with the exception that, in practice, titles and/or chaptersof U.S. Code are sometimes further sub-divided into a hierarchy of partsor sub-chapters so that the topic tree is not balanced and is morecomplex. Nevertheless, the topical unit 26 in this embodiment remains asection of the U.S. Code, and the subject matter units 14 are versionsor instances of the respective section of the U.S. code.

As shown in FIG. 5, each TOC document 102 includes references to alllineal ancestors and descendants in the topic tree. For example, the TOCdocument 102C shown in FIG. 5 includes not only document reference 107Bto parent TOC document 102B (a higher level document) and documentreference 107A to the grandparent TOC document 102A (another higherlevel document), but also references 108 to child or descendantdocuments 104A, B, C, D (lower level documents). This enables thecomplete hierarchical path of the TOC document 102C to be readilydisplayed, as discussed below.

In the preferred embodiment, a legal database 100 is implemented throughthe use of structured documents created with a markup language such asXML. XML tags are used to delineate or differentiate between referencesto ancestral documents and references to descendant documents.

In the preferred embodiment, each document reference 108 (FIG. 5) in aTOC document 102 comprises or is associated with the following dataelements, which are distinguished by XML tags:

-   -   A label 110 that provides a name for display during navigation        by a user through the topic tree or TOC structure. The label        name preferably accurately reflects the substance of the        referenced TOC or subject matter document. In the preferred        embodiment, each label is a heading (or instance thereof) in the        table of contents to the U.S. Code. For example, if the        referenced document relates to section 78g of Title 15 (i.e., 15        U.S.C. §78g) as of Sep. 21, 2001, the label is “Sec. 78g. Margin        requirements.” The label is preferably appropriately tagged (not        shown) in XML (and/or HTML prior to being interpreted by a        browser) so as to enable the browser to display the name as an        actuatable hypertext link.    -   A filename 112 that specifies the location of the referenced TOC        document or subject matter document in the database 100. If        desired, a URL (universal resource locator) may be employed, for        example, where the documents 102 or 104 are located across a        network. The symbols “<>” schematically indicate in FIG. 5 that        the bracketed information, such as the filename 112, comprises        or consists of non-displayable control information.    -   Date parameters 114 that specify the temporal scope or        applicability of the referenced TOC documents 102 or subject        matter documents 104. For TOC documents disposed at leaf nodes        of the topic tree, the date parameters are those described below        with reference to subject matter documents 104. A less extensive        set of date parameters may be employed for TOC documents        logically positioned at a hierarchically higher level of the        topic tree.

The hierarchy of TOC documents 102 in FIG. 5 represents the table ofcontents of the U.S. Code, as it evolves over time. Consequently,headings of the table of contents are organized in a multi-levelhierarchy in which each heading, other than an atomic headingrepresenting a topical unit, is associated with at least one descendantor dependent child heading.

Each subject matter document 104 (FIG. 5) includes, or references, orrepresents a version j of a section S_(i) of the U.S. Code. In thepreferred embodiment, subject matter documents 104 include the followingelements, distinguished by XML tags:

-   -   The text 116 of S_(i,j) for display purposes. The text 116 may        include a differentially marked format where available, as        discussed below. The text can also include congressional or        legislative notes about the law for explanatory purposes, as        well as a reference to the public law that gave birth to the        section. This additional material is preferably tagged and        displayed on request, as discussed below.    -   A document reference 118 to the parent TOC document 102C, which        represents a topical unit. Document references 118 incorporate        data elements 110-114 as previously described.    -   An adoption date (“T_(a)”) representing the date on which the        section, or more generally, the law or regulation enacting the        section, is adopted, enacted or passed. In this sense, T_(a)        matches the law or regulation enacting a section to the section.        The adoption date is also used to order versions or instances of        the same section of law. For example, S_(i,j+1) adopted on Jan.        10, 1970 would replace S_(i,j) adopted on Jan. 1, 1960. The        adoption date can be before, during, or after the effective        temporal range of a section of law.    -   An initial effective date (“T_(ie)”) representing the date on        which the section will or does first take effect. This date may        differ from the adoption date, T_(a), of that section and may        also be contingent on an event whose date is not certain on the        adoption date.    -   An initial termination date (“T_(it)”) representing the last        date on which the section will be effective as determined on the        adoption date, T_(a). T_(it) will usually be “infinity”, i.e.,        in perpetuity, or indefinite. Like the initial effective date,        T_(ie), the initial termination date T_(it) may also be        contingent or uncertain.    -   A final effective date (“T_(fe)”) representing the first date on        which the section is in force as a result of a new law or        regulation. Subsequent to the adoption date T_(a) of a section        S_(i,j), a new law or regulation may be passed that causes the        section to be in force for a time other than an initial        effective interval, e.g., between the initial effective date,        T_(ie), and the initial termination date, T_(it). The “final        effective date”,T_(fe), may differ from the initial effective        date, T_(ie).    -   A final termination date (T_(ft)) representing the last day on        which a section is in force as a result of passage of a new law        or regulation. Generally, this date is different from the        initial effective date, T_(ie), but does not necessarily need to        be.

The foregoing date information provides a mechanism for determining thetemporal applicability of a given section of the U.S. Code, as well asmaintaining historical information that may be useful to researchers. Anexample of this is shown in FIGS. 6A-6C. FIG. 6A illustrates thesituation when a section, S_(i,j), of the U.S. Code is first passed orfirst entered into the database 100. As is typical, the public lawcausing S_(i,j) to come into existence is adopted on a particular datet₀ and states that S_(i,j) will become effective at a later date t₁, andremain in effect indefinitely, i.e., the initial and final terminationdates T_(it) and T_(ft), are indefinite, infinity or in perpetuity.Hence, T_(a)=t₀, T_(ie)=t₁, T_(fe)=t₁, T_(it)=∞, and T_(ft)=∞, and thedate range associated with S_(i,j) is T_(fe) to T_(ft) or t₁ to ∞.

In FIG. 6B, another law is adopted at time t₂ (represented by S_(i,j+1)in the lower time line), which, when it becomes effective at time t₃,causes a change to the text of S_(i,j). A new document is created,represented in lower time line of FIG. 6B by S_(i,j+1,) which can be amodification of the original document represented by S_(i,j) in theupper time line of FIG. 6B. In this case, the subject matter documentincluding S_(i,j), should be modified so that T_(ft)=t₃. The timeperiods T_(fe) and T_(ft) indicate when a law is in force and thus theapplicability of S_(i,j) is marked as being only between t₁ and t₃. Thenew subject matter document is represented by S_(i,j+1). In this newdocument, T_(a)=t₂, T_(ie)=t₃, T_(fe)=t₃, T_(it)=∞, and T_(ft) the daterange associated with S_(i,j+1) is t₃ to ∞.

Time t₃ indicates both the time the old law (represented in the uppertime line of FIG. 6B by S_(i,j)) terminates and the time that the newlaw (represented in the lower time line of FIG. 6B by S_(i,j+1)) iseffective. In the database 100, the final termination time t_(ft) willbe represented by T³⁻1 (not shown in FIG. 6B), which is a time justbefore T₃, i.e., “1” represents a fictitious or actual unit of time.This precludes the possibility of the database 100 indicating that thenew and the old law are simultaneously effective. For example, T₃ may be12:01 AM and T³⁻1 may be 12:00 midnight of the previous day. Thus, forexample, the applicability of S_(i,j) ends at 12:00 midnight of December31 and the applicability of S_(i,j+1) starts at 12:01 AM of January 1.

In FIG. 6C, another law is adopted at time t₄ which becomes effective attime t₅ and again modifies the text of this section (i.e., S_(i,j+)1 ismodified). As a result, S_(i,j+1) is modified so that T_(ft)=t₅−1 (“1”is a unit of time as discussed above), and S_(i,j+2) is created withT_(a)=t₄, T_(ie)=t₅, T_(fe)=t₅, T_(it)=∞, and T_(ft)=∞.

In certain cases, the text of the section of code is stored in thesubject matter document 104 using a differentially-marked format (e.g.,a so-called redline version), so that when displayed shows the changesin section. For example, referring to FIG. 6B, the text of the codesection in S_(i,j+1) preferably the includes the text of the codesection of S_(i,j) but marked up with pre-specified XML tags in order toindicate unchanged text, additional text and deleted text. This enablesa browser, for example, to display changes to the section if so desiredby a user, as discussed below. If desired, the historical dateinformation, T_(ie) and T_(if), may be displayed at the same time inorder to indicate the temporal applicability of the previous version orinstance of that section of the Code.

Appendix 1 is a truncated sample of an XML document for 3 U.S.C. §102.“Truncated (#1)” represents additional historical information.“Truncated (#2)” represents the remainder of the concerned amendment.“Truncated (#3)” represents additional references to related public lawsections. “Truncated (#4)” represents additional annotations. The textof 3 U.S.C. §102 is presented in a differential format, where “$200,000”would be displayed stricken and “$400,000” underlined.

Appendix 2 is a truncated sample of an XML document for a TOC of Title3, United States Code. “Truncated (#1)” represents additional chapterdesignations.

“Truncated (#2)” represents the text of additional chapter headings.“Truncated (#3)” represents additional annotations.

The sample XML documents in Appendices 1 and 2 include historicalinformation, related public law information and annotational informationin addition to temporal information.

The System

FIG. 7 depicts one embodiment of a hardware and software system 120employed for accessing an information collection, base or database 10,100 of the type described herein. The system 120 includes a clientcomputer 121 and a server computer 124 coupled through a communicationsnetwork 125. The server computer includes or is coupled to aninformation base or database 100. The client computer 121 includes acomputer display device 129 (e.g., a monitor) on which informationretrieved from the information base and other information can bedisplayed, and an input device 128 (e.g., a keyboard and/or pointer orcursor control device such as a mouse) by which requests and queries andother information can be input to the system 120. The terms “computer”and “devices” are meant herein in a broad sense and, unless the contextindicates otherwise, encompass PCs, MACs, PDAs, cell phones, lap tops,palm tops, handhelds, etc. The terms “request” and “query” are used in abroad sense as described above.

System 120 depicts a client-server system that includes client computers(e.g., PC's, PDAs, etc.) 121 that include a user interface 122, which inthe preferred embodiments includes some type of browser software 122.For example, client computer 121 can include an MS Windows-based clientapplication that interprets and forwards input from an input device 129to the server 124. Alternatively, an Internet-type browser can providethe entire user interface in client computer 121. However, other typesof systems and user interfaces may be used, as will be known to thosehaving ordinary skill in the computer and programming arts.

In the preferred embodiment for implementing a system involving the U.S.Code, a database 100 of data files or documents marked up using one ofthe many markup or formatting languages or specifications, as known inthe art per se, is provided. The markup is used to embed customizedcontrol or formatting information in the document. The documents arepreferably stored in the database 100 accessible with an applicationserver 123. The database 100 and the application server 123 may be partof, or coupled to, the server computer 124. The server computer 124provides documents for delivery over the communications network 125,which may be a private network or a public network such as the Internet,to client computers 121.

In the preferred embodiment, the documents are stored in the database100 in XML format and rendered into HTML by the application server 123for distribution to client computers 121 that execute browser software122. However, the documents may be delivered in XML format to clientcomputers 121 having a plug-in or other such interpreters 126 in orderto interpret the XML specification. Other kinds of markup languages mayalso be employed in practice, and other types of client devices 127 maybe used. Furthermore, the database 100 could be stored on a CD-ROM orthe like and directly accessed by client computers 121 or other devices127. In all of these embodiments, it will be understood that thedatabase 100 is stored on a computer readable medium which isoperatively connected to a computer or to a computer system, comprisingone or more processors, devices or computers, which controls storage,access, retrieval and/or display, or otherwise the visibility ofinformation from the database 100.

FIGS. 8-14 show screens provided by the user interface 122, whichincludes an MS Windows-based client application that includes browsersoftware, on a computer display device 128 included in or coupled to aclient computer 121. FIG. 8 shows a welcoming screen 130 of the U.S.Code information database 100 displayed by the browser 122 when it firstconnects to the server 124. The main components of the browser userinterface comprise a navigational window 132, a display window 134, anda search toolbar 136.

The navigational window 134 (FIGS. 8-10) generally displays the user'scurrent position within the codification structure, i.e., thehierarchical path that the user has navigated through in the topic tree.In this case, the navigational window displays headings in the table ofcontents to the U.S. Code as shown in FIG. 8. As previously described,these headings and links to the corresponding documents are convenientlystored within each TOC document.

The display window 134 in FIGS. 8-10 is generally used to display thenodes or branches of the topic tree that the user may select to continuenavigation through the tree. In the event a leaf node/topical unit isreached, the display window 134 in FIGS. 11-14 displays the dependentsubject matter document. Thus, the display window 134 displays eitherthe organizational or classification structure of the U.S. Code, asrepresented by the table of contents, or the sectional text.

The search toolbar 136 (FIG. 8) provides input fields 136A and 136B fordirect navigation via citation searches by title (136A) and section(136B). The toolbar 136 also includes a date input field, specifically a“cause of action” input field 136C, for specifying the visibility ordisplayability of TOC labels, headings or links in the navigational ordisplay windows 132 and 134 and subject matter documents displayed indisplay window 134. For example, the TOC document 102C in FIG. 5includes references to two “Section 1” subject matter documents 104A and104B. Depending on the date entered in the cause of action field 136C,only one “Section 1” link will be displayed in the navigation window 132and only one subject matter document will be displayed in the displaywindow 134. If no date is entered, the cause of action date 136Cdefaults to the current date.

In alternative embodiments, rather than having a single “cause ofaction” date, it may be desirable to be able to receive a range of datesas an input parameter. In such embodiments, all subject matter documentsand TOC references/labels which fit the specified date range arevisible. This enables the researcher to have ready access to theprovisions of the Code over a range of time.

In forming the welcoming screen 130 (FIG. 8), the browser 122 loads aTOC document 102A (FIG. 5) from the server 124 and displays all thetitles of the U.S. Code applicable as of the cause of action date inputin field 136C. By pointing and clicking, the researcher can select aparticular title of the Code and begin to navigate through the topicaltree inherent in the TOC documents 102. This enables a researcher toquickly move into an area of law of interest.

If a particular title of the Code is selected or otherwise actuated, thebrowser 122 retrieves and loads the appropriate TOC document 102B (FIG.5) from the server 124. FIG. 9 depicts a screen 130A displayed when theuser has selected Title 15 of the United States Code, which results inthe chapters of Title 15 being displayed in the display window 134, andthe hierarchical path through the table of contents being displayed inthe navigation window 132. The server 124 also causes an optionalnavigational toolbar 140 to be displayed in the navigational window 132.This toolbar 140 includes virtual buttons 140A and 140B for movingforward and backward along the currently displayed hierarchical level ofthe topic tree or table of contents. For example, actuating the forwardbutton 140B results in the chapters of Title 16 being loaded anddisplayed. The “top” virtual button 140C scrolls up to the top of thematerial shown in the display window 132. The “notes” virtual button140D provides the user with additional congressional or legislativeinformation concerning the law, this information being stored in the TOCor subject matter document as described above. The “changes” virtualbutton 140E provides the user with a differential-format text display asdiscussed below in connection with FIG. 14. The “navigation off” virtualbutton 140F removes the navigational window 124 from the screen displaythereby increasing the size of the display window 134, if desired.

A user can jump or navigate to any of the nodes displayed in windows 132and 134. The navigational process may continue until the user reaches aleaf node in the topical tree, represented in screen 130B in FIG. 10,where the sections of Chapter 2B, Title 15 of the U.S. Code aredisplayed. The hierarchical path through the table of contents isdisplayed in the navigational window 132 as stored in TOC document 102Cloaded by the browser 122. Optionally, this information (hierarchicalpath) can be constructed by following the TOC links up the tree in thecase where the complete hierarchical path is not stored in the TOCdocuments. From the screen 130B depicted in FIG. 10, the user may selectone of the displayed sections to view the corresponding date-filteredsection of the Code, such as Section 78b shown in screen 130C in FIG.11. At this point, pressing the forward or reverse virtual buttons 140Aor 140B will cause the browser 122 to load and display the date-filteredsubject matter documents 104 (FIG. 5) for Section 78c or Section 78a,respectively.

In addition, the search toolbar 136 (FIG. 11) may be used to go directlyto a section of the U.S. Code by means of a citation search. Eachsection of law in the U.S. Code is uniquely citable by title and sectionidentifiers, which are entered in input fields 136A and 136C. FIG. 12shows a screen 130D when the citation for 15 USC §78b has been enteredinto input fields 136A and 136C. Carrying out such a search, the browser122 passes the title and section identifiers to the server 124, and theserver 124, in turn, preferably executes an index search to find therequested subject matter document 104 (FIG. 5) or alternativelytraverses through the topical tree implemented by the TOC documents 102until it finds the leaf TOC document 102C which points to the requestedsubject matter document 104, which document is then communicated to andloaded by the browser software.

The search toolbar 136 (FIG. 9) can also be used to enter the materialfrom a temporal perspective. An arrow icon 136E may be used to changethe “cause of action” date appearing in a box 136C.

In addition to the navigation and citation searches mentioned above, thepreferred embodiments enable word and field searches (user interface notshown in FIGS. 8-14), as known in the art. Furthermore, a “historical”search is preferably also available (user interface not shown in FIGS.8-14), in which the entire database 100 is visible to the user, i.e.,and parts thereof can be selected and displayed.

The screens depicted in FIGS. 8-14 were rendered by a client computer121 (see FIG. 7) that includes an MS Windows-based user interface andInternet browser software 122 for interpreting html documents. Inputcommands entered into the client computer 121 by the input device 129(e.g., a mouse and/or keyboard) are interpreted and passed to the server124 for execution. The server 124 returns responsive html or XMLdocuments that are interpreted by the browser software 122 or the XMLplug-in 126.

Alternatively, a browser 122, such as MS Internet Explorer, may be usedby the client computer 121 as the user interface. In this embodiment,the server 124 is a net server, and the client software is an Internetbrowser which provides all user interface controls and interprets htmldocuments returned by the net server 124.

FIG. 15 depicts a screen 130G rendered by an Internet browser for a“Section History” search request including a title number (“42”) enteredin the title field 136A and a section number (“1885b”) entered in theSection field 136B. The current date (Jan. 4, 2002) appears in gray tonein the date field 136G. The server 124 returns a table 140 havingsection headings 140 for all atomic versions of the section (Section1885b) entered into the section field 136B and the associated start andend dates 144 and 146 for the section versions represented by thedisplayed headings 140. A researcher can then view and select theparticular version that is of interest to him or her. In response to aselection of a particular heading, the server 124 returns the versionrepresented by the selected heading in a screen display similar to thatshown in FIG. 13.

The browser user interface represented by the screen depicted in FIG. 15and the windows-based user interface represented by the screens depictedin FIGS. 8-14 include basically the same user controls, as indicated bythe use of corresponding reference numbers in the different screens. Inaddition, the browser user interface includes a “Search Type” selectionmenu 150, which enables a researcher to select among a “Citation Search”(as generally represented by the screens depicted in FIGS. 8-14), a“Word Search” which allows searching by keywords, and a “SectionHistory” search as represented by the screen depicted in FIG. 15.Programming for configuring the database 100 for word searches and forconducting word searches is known in the art and therefore will not bedescribed herein.

As previously noted the “changes” virtual button 140E (FIG. 9) allowsthe user to view a differential text display that shows how the law waslast modified, if applicable. For example, in screen 130E shown in FIG.13, the text was retrieved by a citation search, for 42 USC §1885b,effective as of Sep. 27, 2000. This version of the law went into effecton Jul. 29, 1998. FIG. 14 shows the screen 130F that arises fromactivating the “changes” function 140E on the navigational toolbar 140of the screen 130E in FIG. 13. Unchanged text is preferably shown in aregular black-colored font; deleted text in a stricken-through font andin another color, e.g., red; and new text in an underlined font in stillanother color, e.g., green. From this display, the researcher can piecetogether the ‘old law’ or the law prior to the new effective date, byreading the black text in conjunction with the red text. In addition theresearcher can read the new law by reading the black text in conjunctionwith the green text. Lastly the researcher can easily compare the twolaws by readily seeing the differences as displayed within the onescreen, thus providing a convenient format of benefit to the researcher.From a technical point of view the differential display is relativelyeasy to generate because, as previously described, the changes to thelaw are tagged and stored within the subject matter document 104, asdiscussed below.

Given the description of the structure of the TOC and subject mattersdocuments in conjunction with the user interface, the programming of anapplication server, which is the software component of the serverresponsive to browser requests, will be readily apparent to thoseskilled in the programming arts.

The legal database 100 has been described in connection with the U.S.Code. However, the database 100 may include bodies of state and federallaw, the U.S. Code of Federal Regulations (“C.F.R.”), bodies ofadministrative laws (or regulations), etc., in lieu of or in addition tothe U.S. Code. In a preferred embodiment, database 100 includes statecodifications and the U.S. C.F.R. Implementation for these bodies of lawwill be apparent to those of skill in the relevant arts from thedisclosure herein.

The screens represented in FIGS. 8-14 show a user interface for statelaw codifications and the U.S. C.F.R. Referring to FIG. 8, a navigationwindow 150 at the left of the screen 130A includes those states whosebody or bodies of laws are included in the database 100. Next to the twoletter abbreviation for each state is a selectable link that navigatesto the body of state law. Selecting one of these links will lead to ascreen similar to screen 130 showing a table of contents for thatstate's laws. A TOC screen for a state's body of law may also beobtained by inputting the state's two letter code into box 152.Similarly, a table of contents screen for the U.S. C.F.R. can beobtained by selecting the CFR button 154. Further navigation and use forstate laws and the U.S. C.F.R. is similar to that described above forthe U.S. Code.

Procedures for maintaining the database 100 include accounting formodifications to existing sections of law, inserting new sections oflaw, and repealing or omitting existing sections of law. Additionalrequirements include transferring sections of law, amending the notes toa section, renumbering a section and re-enacting a section. Similarly,it may be necessary to insert a new entry into the table of contents(TOC), renumber a TOC entry, transfer a TOC entry, and repeal a TOCentry. A maintenance program provides these functions.

FIG. 16 shows the processing steps that can be used to modify anexisting section of the Code (or other body of law) represented by thedatabase 100. To start the process, the operator identifies the affectedsection S_(i,j) by its citation, step 200. This enables the server toretrieve the corresponding subject matter document 104X for sectionS_(i,j), at step 202. At step 204 the operator provides the effectivedate T_(ie) of the modified section, i.e., the date the modified sectionS_(i,j+1), will go into force. At step 206 the server then modifiesT_(ft) and, if applicable, T_(fe), of the original section, S_(i,j+1).Typically, but not always, T_(ft) (of S_(i,j)) is changed toT_(ie)(S_(i,j+1))−1, i.e., the T_(ie) of S_(i,j+1) minus a unit of timeas necessary. For example, the old section terminates at 12:00 midnightof one day and the new section takes effect at 12:01 a.m. of the nextday, in which case the 1 unit of time is one minute and the terminationdate and the new effective date are on successive days. At step 208, thetext of the modified section S_(i,j+1) is entered into the system. Atstep 210 the new text of the modified section S_(i,j+1) is compared (forexample, in a manual operation) with the text of the original sectionS_(i,j) in order to generate an XML-tagged differential text document.

At step 214, the subject matter document 104Y is created for themodified section S_(i,j+1) by incorporating the differential textproduced in step 210 and any congressional or legislative notes providedin step 212, and gives the document a filename using a predeterminednomenclature. During step 214, the subject matter document 104Xrepresenting S_(i,j) is parsed to extract the document reference 113(see FIG. 5) to its parent TOC document 102Z, which will also ownsubject matter document 104Y including the modified section. Thisextracted document reference is written into document 104Y. In addition,the various date elements are written into the document 104Y.Specifically, T_(ie)(S_(i,j+1)) for the original document is set to thestarting date of the amended section, and T_(fe)(S_(i,j+1)) is set toequal T_(ie)(S_(i,j+1))_(j−)1. T_(a)(S_(i,j+1)) is set to the date onwhich the law or regulation which created S_(i,j+1) was enacted.T_(ie)(S_(i,j+1)) is set to the ending date, typically perpetuity, ofthe amended section, and T_(fe)(S_(i,j+1)) is set to T_(ie)(S_(i,j+1)).

At step 216, the server retrieves the TOC document 102Z that will ownsection S_(i,j+1). The parent TOC document 102Z is then modified toincorporate a new reference 108 (see FIG. 5) to subject matter document104Y representing S_(i,j+1). This includes the foregoing date parameterswhich enable the label 110 for Si,j+1 to be appropriately date-filtered.At this point S_(i,j+1) has been fully integrated into the informationbase.

When a new section of the Code arises, the process of incorporating thatsection into the database 100 is similar to that described withreference to FIG. 15. In this case, a new subject matter document 104 iscreated without comparison to a pre-existing subject matter document,and the parent TOC document 102Z is updated to include a reference tothe new subject matter document. In the event the new section(s) iscreated within the framework of a new chapter, part or title of law, oneor more new TOC documents will be created and other TOC documents mayhave to be modified in order to incorporate references to the new TOCdocuments.

A repeal or omission of a section of the Code requires an update to theparent TOC document owning the subject matter document corresponding tothat section. More particularly, the date range of the reference to thesubject matter document in the TOC document is modified to update thefinal termination date, T_(ft).

A transfer of the text of a first section of the Code to a secondsection of the Code is treated as a repeal of the first section and amodification to the second section.

Similar procedures may be followed in modifying, inserting, deleting orrepealing TOC entries.

In the flowchart of FIG. 16, the input steps 200, 204, 208 and 212 havebeen shown and described as separate and manually provisioned inputsteps. However, those skilled in the art will appreciate that the inputdata can be input from a data feed or electronically from a computerreadable medium, as discussed below. Also, input data can be provided inone step and the process repeatedly executed in batch mode.

It is also possible to capture some of the information required toupdate the information base 100 by parsing data files produced by theOffice of the Law Revision Counsel. For example, FIG. 17 shows a table250 of classifications for the U.S. Code produced by the Office of theLaw Revision Counsel, U.S. House of Representatives, and made availableover the Internet. The table describes the affected section of the U.S.Code and the nature of the change, e.g., new section, transfer ofsection, repeal or omission of section, or, by default, modification ofthe section. The public law that caused the section to change is listed,as well as a reference to the Statutes at Large. The public law sets outthe new text of the section, and the date the public law is passedrepresents the date of adoption of the new section. A citation to thepublic law is preferably included within the subject matter document 104so that a hyperlink reference can be provided to the public law. Thistype of class function may or may not be available for state or otherbodies of law, and various sources may have to be examined to obtain theinformation needed to update the body of law.

Variants and Modifications

The legal database 100 described above can be readily adapted for otherbodies of law, in this or other countries. Also, the hierarchy may beextended to incorporate sub-sections or paragraphs. For example, Title37, Part 2, Section 51 of the C.F.R. (i.e., 37 C.F.R. §2.51) is dividedinto subsections (a) and (b) which each are further sub-divided intosub-sub sections (1), (2) and (3). In general, those of skill in the artwill appropriately define atomic units of the subject or body of law andwill form the information or subject matter units and topical units inthe most practical manner. This will depend to some degree upon theexpected extent of modifications to the subject or body of law, as wellas how much of a part of the subject or body of law should be shown inone display screen to provide clear, cohesive and/or unencumbereddisplays to the researcher with sufficient context to avoid “gettinglost” during navigation.

Further, different or additional user interface screens may be provided.For example, a drop down date version of a list may be provided for asection or section heading that is displayed. Selection of a date ofinterest would result in display of the section version associated withthe selected date. The date list may be populated from a centralrepository rather than from discrete structured documents.

The foregoing embodiments have described in detail an informationcollection defining a body of law, e.g., the U.S. Code. It should beunderstood that the invention is applicable to other bodies ofinformation and subjects, and application of the invention thereto wouldbe apparent to those skill in the relevant arts from the disclosureherein.

Also, although a preferred embodiment of the U.S. Code databasedescribed above employs structured documents, other schemes may be usedfor the U.S. Code database and other information collections. Wherestructured documents are employed, they can be structured using anysuitable markup language, and in other ways, or using non-structureddocuments such as records in a relational database. Also, those skilledin the art will understand that a variety of programming methodologiescan be used to implement a hierarchical information collection, base ordatabase. Similarly, those skilled in the art will appreciate thatnumerous modifications and variations may be made to the embodimentsdescribed herein without departing from the spirit and scope of theinvention.

APPENDIX 1 SAMPLE XML DOCUMENT (TRUNCATED) FOR TITLE 3, UNITED STATESCODE, SECTION 102 <USCODE> <WHOWASI[SF1]>03/03_26</WHOWASI><TOCFILE[SF2]>TocUSCTITLE3CHAPTER2</TOCFILE><DATE[SF3] >01/05/1999</DATE> - <ASENACTED[SF4]><FILENAME[SF5]>3USC102_20010120_a[SF6]</FILENAME> <PL[SF7]> Pub.L.106-58, Sec. 644(a) </PL> <DATESTATUS[SF8] >Enacted? =Effective</DATESTATUS> <DATE_ENACTED>01/20/2001</DATE_ENACTED><DATE_EFFECTIVE[SF9]> 01/20/2001</DATE_EFFECTIVE> <UNCERTAIN[SF10]>thefirst show of the season</UNCERTAIN><DATE_TERMINAL[SF11]>12/31/2999</DATE_TERMINAL> </ASENACTED> -<ASAMENDEDI[SF12]> <FILENAME[SF13]>3USC102_20010120_a</FILENAME>  <PL>Pub.L. 106-58, Sec. 644(a) </PL> <DATESTATUS>Enacted? =Effective</DATESTATUS> <DATE_ENACTED>01/20/2001</DATE_ENACTED> <DATEEFFECTIVE[SF14]>01/20/2001</DATE EFFECTIVE><DATE.TERMINAL>12/31/2999</DATE_TERMINAL> </ASAMENDED><AMENDEDBY[SF15]/> - <LEGISLATIVE_HISTORY> - <HISTORICAL[SF16]><FILENAME>3USC102_19780102_a</FILENAME>  <PL>Pub. L. 95-570, Sec.5(a)</PL> <DATESTATUS>Effective? = Enacted </DATESTATUS><DATE_ENACTED>1/2/1978</DATE_ENACTED><DATE_EFFECTIVE>1/2/1978</DATE_EFFECTIVE><DATE_TERMINAL>01/19/2001</DATE_TERMINAL> </HISTORICAL></LEGISLATIVE_HISTORY> <NAME[SF17]>Sec. 102. Compensation of thePresident</NAME> - <RULE> - <STATUTE[SF18] xml:space=“preserve”> ThePresident shall receive in full for his services during the term forwhich he shall have been elected compensation in the aggregate amountof - <S> <STRIKE>$200,000</STRIKE> </S> <SPACE /> <U>$400,000</U> ayear, to be paid monthly, and in addition an expense allowance of$50,000 to assist in defraying expenses relating to or resulting fromthe discharge of his official | duties, for which expense allowance noaccounting, other than for income tax purposes, shall be made by him. Heshall be entitled also to the use of the furniture and other effectsbelonging to the United States and kept in the Executive Residence atthe White House. </STATUTE> - <EXTRA> - <SOURCE xm1:space=“preserve”> -<HIST_LIST[SF19]> - <HIST ITEM>  <HIST_DATE_ENACTED>June 25,  1948</HIST_DATE_ENACTED>  ′ <HIST_SECTION>ch.644</HIST_SECTION>  ′<HIST_STATUTE>62 Stat.   678</HIST_STATUTE> </HIST_ITEM> ; TRUNCATED(#1) </HIST_ITEM_LAST> - <HIST_ITEM LAST> <HIST_PL[SF20]>Pub. L. 106-58,Sec. 644(a,b)</HIST_PL> ′<HIST_DATE_ENACTED[SF21]>Sept. 29,1999</HIST_DATE_ENACTED> ′<HIST_STATUTE[SF22]>113 Stat.478</HIST_STATUTE> </HIST_ITEM_LAST> . </HIST_LIST> </SOURCE> -<MISC1[SF23] xml:space=“preserve”> AMENDMENTS 1978 - Pub. L. 95-570substituted “Executive Residence at the White House” for “ExecutiveMansion”. 1969 - Pub. L. 91-1 substituted “$200,000” for “$100,000”.1951 - Act Oct. TRUNCATED (#2) - <PUBLIC_LAW><PUBLIC_LINK[SF24]>publ277.105.txt</PUBLIC_LINK> Pub. L. 105-277</PUBLIC_LAW> , div. A, title I, Sec. 101(h) (title III), Oct. 21, 1998,112 Stat. 2681-480, 2681-492. - <PUBLIC_LAW><PUBLIC_LINK>publ61.105.txt</PUBLIC_LINK> Pub. L. 105-61 </PUBLIC_LAW> ,title III, Oct. 10, 1997, 111 Stat. 1290. - PUBLIC_LAW><PUBLIC_LINK>publ208.304.txt</PUBLIC_LINK> Pub. L. 104-208 </PUBLIC_LAW>, div. A, title I, Sec. 101(f) (title III), Sept. 30, 1996, 110 Stat.3009-314, 3009-326. - PUBLIC_LAW><PUBLIC_LINK>pub152.104.txt</PUBLIC_LINK> Pub. L. 104-52 </PUBLIC_LAW> ,title III, Nov. 19, 1995, 109 Stat. 477. Pub. L. 103- 329, title III,Sept. 30, 1994, 108 Stat. 2392. Pub. TRUNCATED (#3) </EXTRA> </RULE>- <ANNOTATION type=“flndings[SF25]”> - <PUBLIC_LAW PIECE> <PL_SESSION/><PL_LAW /> <PL_SECTION /> </PUBLIC_LAW_PIECE> <ADOPTED_DATE/><EFFECTIVE_DATE/> <TERMINATION_DATE>12/31/2999</TERMINATION_DATE><TEXT/> </ANNOTATION> - <ANNOTATION type=“appropriations[SF26]”>- <PUBLIC_LAW_PIECE> <PL_SESSION/> <PL_LAW /> <PL_SECTION /></PUBLIC_LAW_PIECE> <ADOPTED_DATE/> <EFFECTIVE_DATE/><TERMINATION_DATE>12/31/2999</TERMINATION_DATE> <TEXT /> </ANNOTATION>- <ANNOTATION type=“popularName[SF27]”> - <PUBLIC_LAW_PIEC E><PL_SESSION/> <PL_LAW /> <PL_SECTION /> </PUBLIC_LAW_PIECE><ADOPTED_DATE/> <EFFECTIVE_DATE/><TERMINATION_DATE>12/31/2999</TERMINATION_DATE> <TEXT /> </ANNOTATION>- <ANNOTATION type=“effective Date[SF28]”> - <PUBLIC LAW PIECE><PL_SESSION /> <PL_LAW /> <PL_SECTION /> </PUBLIC_LAW_PIECE><ADOPTED_DATE/> <EFFECTIVE_DATE/><TERMINATION_DATE>12/31/2999</TERMINATION_DATE> TRUNCATED (#4)

SAMPLE XM DOCUMENT (TRUNCATED) FOR TOC OF TITLE 2, UNITED STATES CODE<?xml version+‘1.0’?> <!DOCTYPE USTOC SYSTEM ‘./../common/ustoc.dtd’> <USTOC> <WHOWASI>02/02 1</WHOWASI><TOCFILE?toc/title00/TocUSC</TOCFILE> <HIERARCHY> <TOCENTRY><NAME>U.S.Code</NAME> <PL> </PL><DATESTATUS>Effective?=Enacted</DATESTATUS><DATE_ENACTED>01/05/1999</DATE_ENACTED><DATE_EFECTIVE>01/05/1999</DATE_EFECTIVE><DATE_TERMINAL>12/31/2999<DATE_TERMINAL><WHOAMI>toc/titlle00/TocUSC</WHOAMI> </TOCENTRY> <TOCENTRY> <NAME>TITLE2 - THE CONGRESS </NAME> <PL> </PL><DATESTATUS>Effective?=Enacted</DATESTATUS><DATE_ENACTED>01/05/1999</DATE_ENACTED><DATE_EFECTIVE>01/05/1999</DATE_EFFECTIVE><DATE_TERMINAL>12/31/2999</DATE_TERMINAL><WHOAMI>toc/title02//TocUSCTit02</WHOAMI </TOCENTRY> </HIERARCHY><CHILDREN> <TOCENTRY> <NAME>CHAPTER 1 - ELECTION OF SENATORS ANDREPRESENTATIVES</NAME> <PL> </PL><DATESTATUS>Effective?=Enacted</DATESTATUS><DATE_ENACTED>01/05/1999</DATE_ENACTED><DATE_EFFECTIVE?01/05/1999</DATE_EFFECTIVE><DATE_TERMINAL>12/31/2999</DATE_TERMINAL><WHOAMI>toc/title02/TocUSCTit02ChaP1</WHOAMI> </TOCENTRY> <TOCENTRY><NAME>CHAPTER 2 - ORGANIZATION OF CONGRESS</NAME> <PL> </PL><DATESTATUS>Effective?=Enacted</DATESTATUS><DATE_ENACTED>01/05/1999</DATE_ENACTED><DATE_EFFECTIVE>01/05/1999</DATE_EFFECTIVE><DATE_TERMINAL>12/31/2999</DATE_TERMINAL><WHOAMI>toc/title02/TocUSCTit02Chap2</WHOAMI> </TOCENTRY> <TOCENTRY><NAME>CHAPTER 3 - COMPENSATION AND ALLOWANCES OF MEMBERS</NAME><PL> </PL> <DATESTATUS>Effective?=Enacted</DATESTATUS><DATE_ENACTED>01/05/1999</DATE_ENACTED><DATE_EFFECTIVE>01/05/1999</DATE_EFFECTIVE><DATE_TERMINAL>12/31/2999</DATE_TERMINAL><WHOAMI>toc/title02/TocUSCTit02Chap3</WHOAMI> </TOCENTRY> TRUNCATED (#1)</CHILDREN> <RULE> <EXTRA> <MISC1 xml:space=“preserve”> Chap. C. 1.Election of Senators and Representatives  1 2. Organization of Congress21 3. Compensation and Allowances of Members 31 4. Officers andEmployees of Senate and House of Representative s 60 5. Library ofCongress 1 31 6. Congressional and Committee Procedure; Investigations 190 7. Contested Elections (Repealed) 2 01 8. Federal Corrupt Practices(Repealed) 2 41 8A. Regulation of Lobbying (Repealed) 2 61 9. Office ofLegislative Counsel 2 71 9A. Office of Law Revision Counsel 2 TRUNCATED(#2) 01 23. Government Employee Rights 12 01 24. CongressionalAccountability 13 01 25. Unfunded Mandates Reform 15 01 26. Disclosureof Lobbying Activities 16 01 </MISC1> </EXTRA> </RULE> <ANNOTATIONtype=“findings”> <PUBLIC_LAW_PIECE> <PL_SESSION> </PL_SESSION><PL_LAW> </PL_LAW> <PL_SECTION> </PL_SECTION> </PUBLIC_LAW_PIECE><ADOPTED_DATE> </ADOPTED_DATE> <EFFECTIVE_DATE> </EFFECTIVE_DATE><TERMINATION_DATE?12/31/1999</TERMINATION_DATE> <TEXT> </TEXT></ANNOTATION> <ANNOTATION type=“appropriations”> <PUBLIC_LAW_PIECE><PL_SESSION> <PL_SESSION> <PL_LAW> </PL_LAW> <PL_SECTION> </PL_SECTION></PUBLIC_LAW_PIECE> <ADOPTED_DATE> </ADOPTED_DATE><EFFECTIVE_DATE> </EFFECTIVE_DATE><TERMINATION_DATE>12/31/2999</TERMINATION_DATE> <TEXT> </TEXT></ANNOTATION> TRUNCATED (#3)

1. A computer readable medium encoded with one or more data structuresrepresenting an information collection comprising a body of law, the oneor more data structures organizing the information collection andfacilitating computer access from the computer readable medium ofinformation relating to the body of law, the body of law comprising aplurality of topics and a plurality of parts, including parts that aredifferent versions of each other, the one or more data structurescomprising: an association of each part of the body of law, includingdifferent versions thereof, and at least one topic, the associationcomprising a hierarchical arrangement of topics of the body of law andparts of the body of law in which each part of the body of law and anydifferent version thereof and the associated at least one topic arehierarchically associated; an association of temporal informationcomprising one or more dates indicating the legal applicability of arespective part and of the legal applicability of any different versionthereof and the respective part of the body of law or respectivedifferent version thereof; and an association of information relating toeach part and version of the body of law and the at least one topic withwhich the respective part or version is associated.
 2. A computerreadable medium according to claim 1, wherein the the one or more datastructures enable computer access to a part or version of the body oflaw based at least on the temporal information associated therewith. 3.A computer readable medium according to claim 1, wherein the temporalinformation includes a date range, and wherein the one or more datastructures enable computer access to a part or version of the body oflaw based at least on a date encompassed by the date range associatedwith that part of the body of law.
 4. A computer readable mediumaccording to claim 1, wherein the temporal information comprises a dateon which that part or version of the body of law was adopted.
 5. Acomputer readable medium according to claim 1, wherein the informationrelating to each part of the body of law associated with at least onetopic comprises the temporal information.
 6. A computer readable mediumaccording to claim 1, wherein the association of the informationrelating to each part of the body of law and at least one topiccomprises the at least one topic including such information.
 7. Acomputer readable medium encoded with one or more data structuresrepresenting an information collection comprising a body of law, the oneor more data structures organizing the information collection andfacilitating computer access from the computer readable medium ofinformation relating to the body of law, the one or more data structurescomprising: one or more unique information units, each information unitincluding at least one part of the body of law, including any differentversion of the at least one part, and a plurality of topical units, eachcomprising at least one topic arranged in a scheme for organizing aplurality of interrelated topics; an association of each topical unitand the at least one information unit, each topical unit includinginformation relating to the at least one information unit associatedtherewith; and an association of temporal information comprising one ormore dates indicating the legal applicability of each part of the bodyof law and different version thereof and the respective information unitin which information unit the respective part and any different versionthereof are included.
 8. A computer readable medium according to claim7, wherein the the one or more data structures enable computer access toan information unit based at least on the temporal informationassociated therewith.
 9. A computer readable medium according to claim7, wherein the the one or more data structures enable computer access toan information unit based at least on the temporal informationassociated therewith.
 10. A computer readable medium according to claim7, wherein the association of each information unit and temporalinformation comprises each information unit including the associatedtemporal information.
 11. A computer readable medium according to claim7, comprising at least one link between each information unit and thetemporal information associated therewith.
 12. A computer readablemedium according to claim 7, wherein each information unit comprises astructured document including a part or version of the body of law andthe temporal information associated therewith.
 13. A computer readablemedium according to claim 7, wherein the one or more data structurescomprises a relational database including records, and each informationunit and the temporal information associated therewith are included in arespective record.
 14. A computer readable medium according to claim 7,wherein the one or more data structures comprises a plurality of files,each file storing at least one information unit and the temporalinformation associated therewith.
 15. A computer readable mediumaccording to claim 7, wherein the one or more data structures comprisesa plurality of files, each file storing at least one topical unit, eachinformation unit associated therewith, and the respective temporalinformation associated with each information unit associated therewith.16. A computer readable medium according to claim 7, wherein the one ormore data structures comprises a hierarchical arrangement of topicalunits and associated information units.
 17. A computer readable mediumaccording to claim 7, wherein the association of the topical unit andthe temporal information associated with at least one of the informationunits associated with the respective topical unit comprises the topicalunit including the temporal information.
 18. A computer readable mediumaccording to claim 7, wherein the one or more data structures comprisesa hierarchical organization comprising a topic tree that comprises aplurality of nodes, with each node representing one of the topicalunits, the tree having leaf nodes representing topical units, eachtopical unit being an atomic topical unit that is not subdivided, andwherein each information unit associated with a respective topical unitis associated with the leaf node representing that topical unit.
 19. Acomputer readable medium according to claim 7, wherein the the one ormore data structures comprises at least one table of contents (TOC)associated with the topical units, each TOC including a reference toeach information unit associated with the respective topical unit.
 20. Acomputer readable medium according to claim 1 or 7, wherein the temporalinformation includes a date range.
 21. A computer readable mediumaccording to claim 7, wherein the temporal information includes a daterange, and wherein the one or more data structures enable computeraccess to an information unit based at least on a date encompassed bythe date range associated with that information unit.
 22. A computerreadable medium according to claim 1 or 7, wherein the temporalinformation comprises a date range including a date on which the relatedpart of the body of law is effective, and, if that part of the body oflaw has a date of termination, the date of termination.
 23. A computerreadable medium according to claim 7, wherein the temporal informationcomprises a date on which the part or version of body of law included inthe respective information unit was adopted.
 24. A computer readablemedium according to claim 1 or 7, wherein the body of law includes atleast one title of the United States Code.
 25. A computer readablemedium according to claim 1 or 7, wherein the body of law includes atleast one title of the United States Code of Federal Regulations.
 26. Acomputer readable medium according to claim 1 or 7, wherein the body oflaw includes at least one title of a codified set of laws of at leastone state.
 27. A method of providing the one or more data structures ofclaim 7 comprising: associating each information unit with applicabletemporal information; organizing the information units into topicalunits at least one of which includes the plurality of information unitshaving different versions of the same part of the body of law; andconfiguring the one or more data structures to provide access by acomputer, in response to at least one request input to the computeridentifying a topical unit and a date, to an information unit of theidentified topical unit having temporal information associated therewiththat encompasses the date.
 28. A computer readable medium according toclaim 7, wherein the information relating to each information unitassociated with at least one topical unit comprises the temporalinformation.
 29. A computer readable medium according to claim 7,wherein the association of the information relating to each informationunit and at least one topical unit comprises the at least one topicalunit including such information.
 30. A computer readable medium encodedwith one or more data structures representing an information collectioncomprising a body of law, the one or more data structures organizing theinformation collection and facilitating computer access from thecomputer readable medium of information relating to the body of law, theone or more data structures comprising: a plurality of structureddocuments arranged in a hierarchy of documents comprising documentsincluding a topic or topics of the body of law and documents including apart of the body of law; an association of each of the documentsincluding a part of the body of law and temporal information comprisingone or more dates indicating the legal applicability of the respectivepart, wherein a plurality of the parts of the body of law comprisesdifferent versions of the same part of the body of law; and eachdocument that includes a part of the body of law including any differentversion of that part of the body of law and the temporal informationassociated with the respective part or version.
 31. A computer readablemedium encoded with one or more data structures representing aninformation collection comprising a body of law, the one or more datastructures organizing the information collection and facilitatingcomputer access from the computer readable medium of informationrelating to the body of law, the one or more data structures comprising:a plurality of lower-level structured documents; an association of eachof a plurality of parts of the body of law and temporal informationcomprising one or more dates indicating the legal applicability of therespective part, wherein a plurality of the parts of the body of lawcomprises different versions of the same part of the body of law, thetemporal information being different for different versions of the samepart of the body of law; each lower level structured document includinga different part or different version of the same part of the body oflaw and including the associated temporal information; and at least onehigher level structured document, each lower level structured documentbeing in a hierarchical relationship with at least one higher levelstructured document which higher level structured document includesinformation relating to the respective lower level structured document.32. A method of providing the one or more data structures of claim 31,comprising: associating each part of the body of law with applicabletemporal information; including each part of the body of law and itsassociated temporal information into a lower level structured document;associating applicable lower level structured documents with a higherlevel structured document; including in each higher level documentinformation relating to each lower level document associated therewith;and configuring the one or more data structures to provide access by acomputer, in response to at least one request input to the computeridentifying a part of the body of law and a date, to a structureddocument including the identified part and temporal informationassociated therewith that encompasses the date.
 33. A computer readablemedium encoded with one or more data structures representing aninformation collection related to a common subject, the one or more datastructures organizing the information collection and facilitatingcomputer access from the computer readable medium of informationrelating to the common subject, the one or more data structures,comprising: a plurality of lower level structured documents; anassociation of each of a plurality of parts of the common subject andtemporal information comprising at least one date indicating a state orstatus with respect to time of the respective part of the commonsubject, wherein a plurality of the parts of the common subjectcomprises different versions of the same part of the common subject, thetemporal information being different for different versions of the samepart of the common subject; each lower level structured documentincluding a different part or different version of the same part of thecommon subject and including the associated temporal information; and atleast one higher level structured document, each lower level structureddocument being in a hierarchical relationship with at least one higherlevel structured document which higher level structured documentincludes information relating to the respective lower level structureddocument.
 34. A computer readable medium according to claim 31 or 33,wherein at least one higher level structured document includes a tableof contents (TOC) including a reference to each lower level structureddocument associated therewith.
 35. A computer readable medium accordingto claim 34, wherein at least one higher level structured documentincludes a TOC having a reference to at least one other higher levelstructured document hierarchically related to the at least one higherlevel structured document in an ancestral/descendant relationship.
 36. Acomputer readable medium according to claim 34, wherein at least onehigher level structured document includes a TOC having a reference to atleast one other higher level structured document and to each lower levelstructured document referenced by the at least one other higher levelstructured document, the at least one higher level structured documentbeing hierarchically related in an ancestral/descendant relationshipwith the at least one other higher level structured document, and eachof the lower level structured documents.
 37. A computer readable mediumaccording to claim 31 or 33, wherein at least one structured documentindicates differences between different versions of the same part.
 38. Acomputer readable medium encoded with one or more data structuresrepresenting an information collection comprising a body of law, the oneor more data structures organizing the information collection andfacilitating computer access from the computer readable medium ofinformation relating to the body of law, the one or more datastructures, comprising: a hierarchical arrangement of headings in atleast one table of contents (TOC) and parts of the body of law, eachheading identifying one or more parts of the body of law; an associationof temporal information comprising one or more dates indicating thelegal applicability of a respective part of the body of law and therespective part of the body of law; an association of a plurality ofparts of the body of law that are different versions of each other andhave different temporal information associated therewith and at leastone heading of a TOC; and an association of the temporal informationrelating to each part and version of the body of law and each headingwith which the respective part or version is associated.
 39. A computerreadable medium according to claim 38, wherein the one or more datastructures enable computer access to a part of the body of law inresponse to a request by a computer including at least a date of the oneor more dates associated with that part.
 40. A computer readable mediumaccording to claim 38, wherein the one or more data structures include astructured document for and including each different part of the body oflaw.
 41. A computer readable medium according to claim 40, wherein eachTOC is included in a structured document having a reference to eachother structured document including a part of the body of law referencedin a heading of that TOC.
 42. An information storage and retrievalsystem, comprising: a computer system including a computer displaydevice, a computer input device and a computer-readable medium, thecomputer system being coupled to access data stored on thecomputer-readable medium, wherein the medium being encoded with one ormore data structures representing an information collection comprising abody of law, the one or more data structures organizing the informationcollection and facilitating access by the computer system of informationfrom the medium relating to the body of law, the one or more datastructures comprising: an association of each part of the body of law,including different versions thereof, and at least one topic comprisinga hierarchical arrangement of topics of the body of law and parts of thebody of law in which each part of the body of law and different versionthereof and the associated at least one topic are hierarchicallyassociated; and an association of temporal information comprising one ormore dates indicating the legal applicability of a respective part andthe legal applicability of any different version thereof and therespective part of the body of law or respective different versionthereof, wherein the computer system being programmed to access themedium and cause to be displayed on the computer display device, inresponse to input from the computer input device, informationidentifying at least two parts of the body of law that are differentversions of each other together with temporal information associatedtherewith, and in response to input from the computer input deviceselecting one of the identified parts displayed identity to access themedium and cause the one identified part to be displayed on the displaydevice.
 43. An information storage and retrieval system, comprising: acomputer system including a computer display device, a computer inputdevice and a computer-readable medium, the computer system being coupledto access data stored on the computer-readable medium; the medium beingencoded with one or more data structures representing an informationcollection comprising a body of law, the one or more data structuresorganizing the information collection and facilitating access by thecomputer system of information from the medium relating to the body oflaw, the one or more data structures comprising: a hierarchicalarrangement of headings in at least one table of contents (TOC) andparts of the body of law, each heading identifying one or more parts ofthe body of law; an association of temporal information comprising oneor more dates indicating the legal applicability of a respective part ofthe body of law and the respective part of the body of law; and anassociation of a plurality of parts of the body of law that aredifferent versions of each other and have different temporal informationassociated therewith and at least one heading of a TOC; the computersystem being programmed to access the medium and cause to be displayedon the computer display device, in response to input from the computerinput device at least one heading, at least one part associated with theat least one heading and temporal information, and the computer systembeing programmed to cause to be displayed on the computer display devicea displayed part selected with the computer input device that hastemporal information associated therewith that encompasses the displayedtemporal information.
 44. A method of accessing an informationcollection stored on a computer readable medium using a computer coupledto access the information collection, the medium being encoded with oneor more data structures representing an information collectioncomprising a body of law, the one or more data structures organizing theinformation collection and facilitating access by the computer system ofinformation from the medium relating to the body of law, the one or moredata structures comprising; an association of each part of the body oflaw, including different versions thereof, and at least one topiccomprising a hierarchical arrangement of topics of the body of law andparts of the body of law in which each part of the body of law and anydifferent version thereof and the associated at least one topic arehierarchically associated; and an association of temporal informationcomprising one or more dates indicating the legal applicability of arespective part and the legal applicability of any different versionthereof and the respective part of the body of law or respectivedifferent version thereof; the method comprising: displaying on acomputer display device coupled to the computer dates in associationwith information identifying at least two parts that are differentversions of each other; and displaying on the computer display devicethat part of the body of law that is selected with a computer inputdevice coupled to the computer.
 45. A method of accessing an informationcollection stored on a computer readable medium using a computer coupledto access the information collection, the medium being encoded with oneor more data structures representing an information collectioncomprising a body of law, the one or more data structures organizing theinformation collection and facilitating access by the computer system ofinformation from the medium relating to the body of law, the one or moredata structures comprising: an association of each part of the body oflaw, including different versions thereof, and at least one topiccomprising a hierarchical arrangement of topics of the body of law andparts of the body of law in which each part of the body of law and anydifferent version thereof and the associated at least one topic arehierarchically associated; and an association of temporal informationcomprising one or more dates indicating the legal applicability of arespective part and the legal applicability of any different versionthereof and the respective part of the body of law or respectivedifferent version thereof; the method comprising: inputting to thecomputer using a computer input device information identifying a part ofthe body of law and a date; and in response thereto, the computercausing the computer display device to display the identified part whichhas temporal information encompassing the inputted date.
 46. A methodaccording to claim 44, wherein the information collection includes atable of contents (TOC) having headings with which one or more parts ofthe body of law are associated, each heading being associated withtemporal information indicating the applicability of parts associatedwith the respective heading, the method comprising: displaying on thecomputer display device a heading and the temporal informationassociated therewith; inputting to the computer using a computer inputdevice a selection of displayed temporal information associated with aheading; and in response thereto, displaying on the computer displaydevice the part of the body of law in the displayed heading associatedwith the temporal information that is selected using the computer inputdevice.
 47. A method for encoding a computer readable medium with one ormore data structures representing an information collection comprising abody of law, the one or more data structures organizing the informationcollection and facilitating computer access from the computer readablemedium of information relating to the body of law, the body of lawcomprising a plurality of topics and a plurality of parts, includingparts that are different versions of each other, the method comprisingcreating in the one or more data structures: an association of each partof the body of law, including different versions thereof, and at leastone topic in a hierarchical arrangement of topics of the body of law andparts of the body of law in which each part of the body of law and anydifferent version thereof and the associated at least one topic arehierarchically associated; an association of temporal informationcomprising one or more dates indicating the legal applicability of arespective part and the legal applicability of any different versionthereof and the respective part of the body of law or respectivedifferent version thereof; and an association of information relating toeach part or version of the body of law and the at least one topic withwhich the respective part or version is associated.
 48. A method forencoding a computer readable medium with one or more data structuresrepresenting an information collection comprising a body of law, the oneor more data structures organizing the information collection andfacilitating computer access from the computer readable medium ofinformation relating to the body of law, the method comprising creatingin the one or more data structures: one or more unique informationunits, each including at least one part of the body of law including anydifferent version of the at least one part, and a plurality of topicalunits, each comprising at least one topic; an association of eachtopical unit and the at least one information unit, each topical unitincluding information relating to the at least one information unitassociated therewith; and an association of temporal informationcomprising one or more dates indicating the legal applicability of eachpart of the body of law and different version thereof and the respectiveinformation unit in which the respective part and any different versionthereof are included; the method comprising storing the one or more datastructures in the computer readable medium.